Apparatus for operating expanding mandrels



1963 o. c. GOCH'ENOUR ETAL 3,

APPARATUS FOR OPERATING EXPANDING MANDRELS 2 Sheets-Sheet 1 Filed Dec. 31, 1956 E h. E2 j= li lfi= 0: M INVENTORS OLIN C.GOCHENOUR ARNOLD e. SHUMAKER ATTORNEY 2 1,963 o. c. GOCHENOUR ETAL 3,107,375

' APPARATUS FOR OPERATING EXPANDING MANDRELS Filed Dec. 31, 1956 v I 2 Sheets-Sheet 2 INVENTORS OLIN C. GOCHENOUR ARNOLD G. SHUMAKER ATTORNEY United States Patent 3,107,875 APPARATUS FOR OPERATING EXPANDING MANDRELS This invention relates to apparatus for operating expanding mandrels. It is more particularly concerned with such apparatus adapted to exert a controlled gripping force on material wound on the mandrel.

Our invention is particularly adapted to mandrels used 3,107,875 Patented Oct. 22, 1963 "ice 4 2 14 which extends outwardly toward the open end of hub 13 so as to define an annular channel 15 whichopens toward the outer end of hub 13. The outer end of hub 13 is provided with a somewhat similar collar 16 which extends inwardly toward the inner end of hub '13 so as to form an annular channel 17 which is open toward the inner end of hub 13. An elongated mandrel segment 20 is formed with a projecting end 21 which fits within channel 15 and a projecting end 22 which tits within channel 17. A coil spring 23 mounted in collar 14 urges end 21 a of segment 20 toward the axis of the mandrel 9 and a for coiling or uncoiling thin steel strip, such as that sui-table for tin plate, and will be described in connection therewith. It will be understood, however, that our invention is applicable to mandrels used for other types of strip, both metallic and nonmetallic.

It is conventional to coil and uncoil thin steel strip at various stages of its manufacture. For this purpose it is necessary to make use of expanding mandrels, that is, mandrels the efiective diameter of which can be reduced so that they can be inserted in coils and then increased so that the mandrel can grip the coil. Expanding mandrels as such are conventional and need not be described in any detail here since they form no part of our invention. Conventional expanding mandrels are caused to expand or collapse by movement parallel to the mandrel axis of a shaft which is concentric with the mandrel itself. It is conventional to use a hydraulic cylinder to operate an expanding mandrel. A hydraulic operator is undesirable in some respects, particularly for a mandrel from which strip is uncoiled.

In the manufacture of tin plate the coils of strip may reach a weight of 30,000 pounds or so and when such a coil is placed on the mandrel for uncoiling the force which the mandrel must exert against the inside of the coil to prevent slipping is quite considerable. As the strip is uncoiled, the force required on the mandrel diminishes, and when the coil is down to a relatively small diameter, the force required on the mandrel is quite small. It is diflicult, however, under mill conditions to maintain a hydraulic system absolutely tight, and if there is leakage past the valves, a hydraulic mandrel operator tends to exert such force upon the last wraps of a coil that the wraps may be caused to move upon each other, which scuifs or chafes adjoining surfaces. Because of this, it is quite common to scrap the last wraps of a coil of tin plate.

It is an object, therefore, of our invention to provide means for operating an expanding mandrel which will not damage the last wraps of a coil being uncoiled from the mandrel. Other objects of our invention will appear in the course of the following description thereof.

The attached figures illustrate an embodiment of our invention presently preferred by us. FIG. 1 is a plan of a number of the elements of our invention. FIG. 2 is an elevation of the elements shown in FIG. 1. FIG. 3 is a plan, partly in section, for the supporting, driving and control means for a conventional expanding mandrel. FIG. 4 is a longitudinal section through a conventional expanding mandrel.

An upright supporting frame 10 is provided with a pair of aligned antifriction bearings 11 and 12 in which is journaled a horizontally disposed hollow shaft 8. On one outer end of the hollow shaft 8 is carried an expanding mandrel designated generally 9. Mandrel 9 includes an elongated hollow hub portion 13 which is affixed to shaft 8. Hub '13 at its inner end is provided with a collar like coil spring 24 set in collar 16 urges end 22 of segment 20 in the same direction. a The outer surface of segment 20 constitutes a portion of the surface of the mandrel which bears against the inside of a coil. The inner surface of segment 20* is provided with an element 26 formed with a plurality of inwardly facing flat surfaced inclined projections 2727. V Slidably mounted upon hub 13 between the hub and element 26 is an elongated element 28 which is provided with a plurality of outwardly facing fiat surfaced inclined projections 29-29 which slide upon projections 27-27 of element 26. Element 28 is also formed with an inwardly extending lug 30 which projects inside hub 13-and into engagement with an aperture in shaft 31 which is slidably mounted within hub 13.

Upright structure 10 is provided with asecond pair of not shown, which rotates mandrel 9.

The end of shaft 31 opposite mandrel 9 extends into a housing 40 provided with a thrust bearing 41 which fits between the flanges of collar 42 aflixed to shaft 31. Housing 40 is formed with a clevis 43 attached to its closed end and clevis 43is connected by pin 44 to link 45-.

Adjoining upright structure 10 is a second bifurcated upright structure 47 in the upper ends of which is journaled a horizontal shaft 48. Attached to this shaft is a downwardly depending lever 49. Link 45 is connected to lever 49 through pin 50 at a point below shaft 48. Structure 47 is provided at its lower end with adjustable screws 52 and 53 positioned on opposite sides of lever 49 so as to engage the lower end of lever 49 at the end of its swing on either side of the vertical and so act as stops therefor. At a position intermediate the bottom of lever 49 and pin 50, lever 49 is connected-through pin 55 with link 56 which in turn is connected through clevis 57 to cylindrical shaft 58. The end of shaft 58 is provided with a thread 59. Thread 59 engages with a like thread cut in nut 60 which is restrained from axial movement by uprights 61, through which shaft 58 passes, and 62. Nut 60 is connected through coupling 63 to gear reducer 64 which in turn is driven by torque motor 65. Shaft 66 of torque motor '65 is provided with a brake drum 67 and brake shoes 68 which may be tightened or loosened against drum 67 by operating means 69.

The operation of our apparatus will now be described,

again with reference to the attached figures. It will be assumed that mandrel 9 is collapsed so that a coil of strip can be placed upon it. In order to engage mandrel 9 against the inside of the coil, torque motor 65 is connected to a source of power and begins to rotate. The rotation of motor shaft '66 through gear reduced 64 and coupling "63 causes nut 60' to rotate on shaft 58. Rotation of the 11l1t '60 upon shaft 58- causes shaft 58 to move axially toward torque motor 65. This movement of shaft 58 is transmitted to lever 49 and causes it to move in the same direction, which in turn pulls housing 40 carrying thrust bearing 41. This bearing transmits the pull of housing 40 to shaft 31 causing it .to move axially within hub 13 toward torque motor 65. As shaft 31 moves, it pushes against lug 30 and moves element 28 along with it, and as the inclined faces 29 29' of element 28 slide over inclined faces 27-27 of element 26, they force element 26 radially outwardly and so carry segment 2t} in the same direction against the inside of the coil.

' It will be understood that mandrel 9 is provided with a plurality of segments 20 which are identical with that described, so that these segments 20 in their expanded position engage the inside of a coil at several points. 1

When the segments 20 of our mandrel 9 are expanded against the inside of the coil with the proper force as exerted by our torque motor '65, we set brake shoes 68 against brake drum 67 by our brake operating means 69 to hold the mandrel in position, and disconnect torque motor 65 from the power line so that current does not flow through its windings while the coil of strip is being payed ofi. The weight of the coil decreases as it is payed oil, but our brake prevents any change in the balance of force between coil and mandrel. Consequently, there is no slippage of the last wraps of the coil and damage thereto.

It is a well-known characteristic of torque motors, which distinguishes them from other motors, that they can'be stalled and still exert torque without damage from the current which flows through their windings in this condition. It is another well-known characteristic of torque motors that by adjustment of the field or armature current the maximum effective torque which they can deliver parallel segments radially expandable into engagement with a coil of strip and con-tractible out of engagement therewith, means for rotating the mandrel to uncoil strip therefrom and means reciprocally movable axially of the mandrel for causing said radial expansion, the improvement comprising an axially movable nonrotating element connected to said reciprocally movable means so as to transmit axial movement only thereto, a torque motor separate from said means for rotating the mandrel, a brake operating on the shaft of the torque motor, means to adjust said brake, and meansfor converting rotary movement of the torque motor to axial movement of the said axially movable element directly proportional to the number of rotations of the torque motor, whereby the pressure exerted by the mandrel on the coil of strip is fixed by the torque of the torque motor.

References Cited in the file of this patent UNITED STATES PATENTS Roney Apr. 21, 1925 Germany Dec. 3, 1953 I 

